Hot tops, feeders or sinking head boxes



Feb. 17, 1959 E. VALLAK 2,873,492 nor TOPS, FEEDERS OR smxmc HEAD BOXESFiled Aug. 21, 1956 Fig. 1

INVENTOR: ENN VALLAK/ United States Patent nor rors, FEEDERS 0R SINKINGHEAD BOXES Enn Vallak, Geneva, Switzerland Application August 21,1956,Serial No. 605,346

1 Claim. c1. 22-147 This invention relates to so called hot tops,feeders or sinking head boxes. Such hot tops are employed in castingmolds, particularly ingot molds, in order to prevent the so called pipefrom arising in the ingot. To this effect it has been proposed to makehot tops of heat insulating, ceramic material, but hot tops of wood andother combustible material are also known in the art, whereby thecombustion heat is utilized as to prevent the top section of the ingotfrom cooling down too rapidly. A particularly useful and suitable hottop design is described in the Swedish Patent No. 142,209, correspondingto my co-pending U. S. patent application Serial No. 351,546, filedApril 28, 1953, which became abandoned on April 26, 1957, according towhich the hot top consists of a combustible material, which at the sametime is porous, i. e. pervious to gases.

When such combustible hot tops are employed, it is of the utmostimportance that the air necessary for the combustion may quickly enterthe inner portions of the hot top material, enabling the combustion toproceed with the desired speed and uniformity.

The main object of my present invention is to effect this task byproviding the combustible or possibly exothermic hot top material withinner ducts or recesses, communicating at least at one end with theatmosphere and permitting an air stream to be supplied to and throughthe inner portions of the hot top. In order to maintain a constantcirculation of air, it is suitable to provide at least two ducts orrecesses, separated by an intermediate wall; one or more of said ductsor recesses serving for the supply of fresh air and the other fordisposing of flue gases.

An embodiment of the device according to the invention is showndiagrammatically on the accompanying drawing, in which:

Figure 1 is a perspective view of a hot top plate seen from the inside;

Figure 2 is a fragmentary vertical sectional view of a portion of aningot mold wall with a hot top plate of the type shown in Fig. 1attached thereto.

The hot top plate is designated with 1 on the drawing and consists ofcombustible material, such as pulverized coke, coal or charcoal, sawdust or the like, which together with a binding agent, such as wastesulphite lye, is formed into plates of desired shape and in such amanner that the plates will become porous, namely pervious to gases sothat, in burning the plate, the flue gases may escape through the wallsof the hot top material without trying to find their way out through themolten metal in the ingot mold 5. According to the embodiment shown, thehot top plate 1 is provided with two recesses or ducts 2, separated byan intermediate wall 3. At the top these recesses 2 communicate with theatmosphere, and at the bottom they communicate with each other through apassage or opening 4. When the hot top is burning, affected by the heatfrom the molten metal of the ingot mold. 5, fresh com bustion air issupplied to one recess 2, as indicated by the arrow to the left of Fig.l, and this air will enter the other recess 2 through the opening 4,whereupon excess air and flue gases escape at the top of the lastmentioned recess, as shown by the arrow to the right of Fig. 1. Thus,inside the hot top a circulation of air is maintained, causing thecombustion to occur faster and more uniformly.

The recesses 2 are preferably disposed on the side of the hot top facingthe ingot mold wall 5. As a matter of course, nothing prevents two ormore ducts or recesses from being arranged in each plate, but it isessential that intermediate walls 3 are arranged in order to obtain aguided air stream through the plate.

The ducts may take the form of a number of separate more or lessvertical channels within the material of the plate, said channelscommunicating With the atmosphere at least at one end and preferably atboth ends, so as to admit air to enter at one end and flue gases toescape at the other end.

The composition of the plate may vary from case to case but in manycases I prefer to utilize the composition described in my pending U. S.application Serial No. 351,546.

What I claim is:

A hot top plate, for use in connection with an ingot mold having anencircling wall, said plate including combustible material and beingadapted to be disposed adjacent the internal surface of said wall, saidplate including two side flanges and a bottom flange connectedtherebetween, and an upright ridge between said side flanges extendingfrom the top of said plate to a point spaced from said bottom flange fora certain distance, said plate with its flanges and ridge being adaptedto define with said internal wall surface an upright U- shaped airchannel having two upright branches and a connecting branchtherebetween, said certain distance being inferior to the distancebetween said ridge and either side flange whereby the connecting branchwill have a smaller cross section than the upright branches, bothupright branches being open on top.

References Cited in the file of this patent UNITED STATES PATENTS1,139,284 Hitt May 11, 1915 1,208,703 Turner et al. Dec. 12, 19161,235,744 Washburn Aug. 7, 1917 1,258,209 Gathrnann Mar. 5, 19181,500,759 Howard et al. July 8, 1924 FOREIGN PATENTS 519,349 Canada Dec.13, 1955 1,084,725 France July 13, 1954

